Enabling Delta Life
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4 Enabling Delta Life ‘What makes managing land and water in deltas different?’ March 2013 Deltares Marcel Marchand Tom Bucx Cees van de Guchte Alterra-Wageningen UR Bart Makaske Wim van Driel To be cited as: M. Marchand, T. Bucx, B. Makaske, C. van de Guchte & W. van Driel (2012). Enabling Delta Life - What makes managing land and water in deltas different? Discussion paper. Delta Alliance and GWP. www.gwp.org / www.delta-alliance.org Enabling Delta Life ‘What makes managing land and water in deltas different?’ Discussion paper Table of contents Chapter 1 Introduction 5 2 What makes deltas different? 7 Framework for Delta Assessment 9 Drivers of change 10 Trends in society 11 Spatial layer model for deltas 11 Management responses for each layer 12 3 Governance characteristics for each layer 13 Analysis of case studies 15 Main issues 17 Measures 19 Governance 20 4 Suggestions for other deltas 22 Table of contents Synthesis of comments and suggestions from workshops 23 Delta challenges 24 Solutions 25 Governance and international cooperation 26 5 Knowledge 26 The GWP-DA initiative 26 Conclusions 27 Deltas provide opportunities for IWRM in practice 27 Delta Assessments 29 6 Towards a Delta Agenda 29 References 30 Annex 1 Case studies 31 Bangladesh: The Delta Development Plan 2012, the Ganga-Brahmaputra-Meghna Delta 32 Benin: Towards designing a Master Plan, the Ouémé Delta 34 Cambodia: The Mekong delta 36 China: The Pearl River Delta comprehensive Regulation Planning, the Pearl River Delta 38 Egypt: The Alexandria 2030 Integrated Urban Water Management (IUWM) plan, the Nile Delta 40 Indonesia: Managing diverse delta systems 42 Thailand: The Town and Country Planning Act, the Chao Phraya Delta 44 Vietnam: The Delta Master Plan, the Mekong Delta 46 Annex 2 48 List of resource persons and Case Studies Introduction Chapter 1 The Global Water Partnership (GWP) jointly with the Delta Alliance, supported by the Netherlands International Development Programme (DGIS), have the intention to jointly explore how to further the sustainable management of deltas. Many of the deltas worldwide host dense human populations and are important centres of economic activity, such as agricultural and industrial production, shipping and mining. Although comprising only some 5% of the land area, deltas have up to ten times higher than world average population densities. And this number is expected to increase rapidly, especially in the heavily populated mega-deltas in Asia. Deltas are relatively young landforms shaped by the interplay of coastal and riverine processes. They are characterized by a mosaic of gradients between land and sea, fresh and saline waters, as well as exposed and sheltered environments. These patterns and dynamic processes are at the basis of the ecosystem services provided by deltas, such as land formation, coastal protection and food from fisheries. Being ‘hotspots’ of human activity, deltas are also vulnerable to changes induced by a range of driving forces, both natural and anthropogenic. Under the uncertainty of the possible impacts of climate change, low lying deltas around the world face challenges to cope with subsidence, flood risk, storms and salinization. Due to on-going urbanization, demographic Enabling Delta Life | ‘What makes managing land and water in deltas different?’ 5 Introduction growth and economic activities, which have to be combined with food production and ecosystem integrity, the demand for sustainable water allocation, water supply and sanitation and sound infrastructure is omnipresent. Competing demands from a variety of sectors and stakeholders require a transparent dialogue and an enabling governance environment for sound decision-making. Assessments for investments are at the core of any delta management framework, whereas cost-benefit analyses addressing both short and long term perspectives are key to develop affordable and no-regret options to intervene as to sustain the well-being of people, their economic activities as well as their safe living environment. Although the above can be said of many water related areas, low lying deltas are most vulnerable to the threats mentioned above, which makes striving for comprehensive and integrated solutions even more urgent. The complex and interrelated issues in deltas may need to be specifically addressed towards developing more resilient and sustainable deltas in the future. This discussion paper describes an integrated framework for delta assessment, the need for specific strategies for deltas, especially as it relates to integrated water resources management, and taking into account the increasing interest for the institutional, socio-economic, financial and awareness-raising aspects. This is the final version of the discussion paper, which has been updated based on comments and suggestions received before, during and after the workshops at the GWP Consulting Partners Meeting and the Stockholm World Water Week in August 2012. 6 Enabling Delta Life | ‘What makes managing land and water in deltas different?’ What makes deltas different? Chapter 2 Ten reasons why deltas require special attention from integrated water management: 1. Most deltas are moderately to extremely vulnerable to sediment deficit. Upstream river developments (such as storage dams) often lead to a reduction of sediment inflow, whereas dikes and embankments often impede lateral sediment dispersion. Together with an on-going sea level rise 24 out of the 33 largest deltas are at serious risk (Syvitski et al., 2009) 2. The geological characteristics of delta soils make them prone to subsidence, exaggerated by anthropogenic extraction of ground water, which can lead to extreme subsidence on the short term. 3. Deltas are relatively young landscapes, featuring highly dynamic geomorphological processes, such as coastal erosion and accretion and river meandering and avulsion. 4. Delta soft soils pose specific challenges to civil infrastructure (such as roads, railways, bridges and tunnels). 5. Their position at the most downstream part of rivers make deltas particularly receptive to water pollution. 6. Flood hazards come from three different sources: fluvial, coastal and pluvial. A combination of high river discharges with heavy rainfall and extreme tide or storm surge may easily result in disastrous consequences. Enabling Delta Life | ‘What makes managing land and water in deltas different?’ 7 What makes deltas different? 7. Droughts in deltas do not only lead to a shortage of water, but also to an increase in seawater intrusion. Fresh groundwater reserves are being threatened with seepage of saline water. 8. Invariably, deltas are the most densely populated places on earth. Most of the world’s megacities are situated in delta areas, and urbanisation rapidly increases. This fact leads to constraints of space and resources, resulting in a multitude of complex and interrelated development and management issues, ranging from spatial urban and land use planning and traffic control to flood protection, land reclamation, water supply and sanitation problems and preservation of nature reserves and ecosystem services. 9. Most deltas contain deposits of fossil fuels (oil, gas), of which their exploitation leads to soil subsidence and environmental challenges, such as risk of leakages and pollution. 10. Delta rivers and estuaries have the highest economic value of all ecosystems. Nutrient recycling and food production are the major functions that contribute to this high value. Typical delta wetlands (mangroves, salt marshes, estuaries) are among the most valuable as well as among the most threatened ecosystems. Many of the issues above are somehow, and often strongly, interrelated. This calls for inclusive, integrated approaches towards delta development, management and governance under the uncertainty of climate change. 8 Enabling Delta Life | ‘What makes managing land and water in deltas different?’ Framework for Delta Assessment Chapter 3 A framework has been developed (figure 1 on next page) for describing deltas in a uniform format which enables a comparison of deltas with regard to sustainability and resilience (Bucx et al., 2010). This framework links the DPSIR approach (OECD, 1993) with a layer model for spatial development (McHarg, 1969, Meyer & Nijhuis, 2010, Marchand & Ruijgh, 2009). The framework also provides a linkage with governance issues and with the different actors and agencies involved in delta development and management. Enabling Delta Life | ‘What makes managing land and water in deltas different?’ 9 Framework for Delta Assessment drivers management response trends in society for change for delta development Occupation Layer economic development development and adaption of risk aversion population land and water use growth participation Network Layer technological extension and development revitalization of privatization infrastructure decentralization Base Layer climate change management environmental subsidence and restoration governance of delta development concerns of natural systems Figure 1 Framework for Delta Assessment Drivers of change Population growth, economic development, climate change and subsidence are the main drivers of change in deltas. These developments pose extensive demands on the available natural resources. But also technological development can be seen as a driver of change: it may provide opportunities for more cost-efficient and innovative infrastructure or exploitation of previously untapped natural resources. Box 1 provides a general description